1. Field of the Invention
The present invention relates generally to optimizing computer performance during a processor's sleep mode of operation.
2. Background
Power dissipation is a major consideration in the design of central processing units (CPUs) and the computers in which they are used. Many computers are configured to enter a “sleep” mode of operation in order to reduce power consumption when processing is not required. Typically, in sleep mode, the computer is rendered inactive and its CPU stops executing instructions. Although the computer is inactive, a limited number of computer devices remain active (e.g., keyboard, mouse, and Universal Serial Bus (USB) ports) and when these devices are triggered by a user input, the computer awakens into an active state. For instance, a keystroke on a keyboard or a click of a mouse may awaken the computer from sleep mode.
However, other computer functions and devices are powered down or inactive during sleep mode. These computer functions and devices include, for example, a display device (e.g., monitor), a network device (e.g., internet connection), and a sound device (e.g., sound adapter). The computer and its CPU must exit its low-power sleep mode of operation before the user can execute these devices.
For computer programs that do not require optimal performance from the CPU, the CPU unnecessarily expends a significant amount of power on these types of applications. This power dissipation is mostly attributed to switching devices in the CPU and energy lost in the form of heat due to a resistivity of electrical circuits. For instance, even though an application executed on the computer may not require a high CPU clock speed, the CPU runs at its high clock speed regardless of the complexity of the application. As the CPU continues to exit sleep mode to execute less computationally intensive applications, the CPU unnecessarily expends more power than required and can increase the risk of device failure, thus decreasing the reliability of the computer.
In addition, for low-power applications such as portable handheld devices, the unnecessary dissipation of power from the CPU drains battery life at a higher rate, thus reducing the performance of the device.
Accordingly, what is needed is an improved apparatus and method to optimize computer performance during a processor's sleep mode of operation.